The number 21301
21301 is a composite number with 8 divisors. Its prime factorisation is 7 × 17 × 179. Divisors (8): 1, 7, 17, 119, 179, 1253, 3043, 21301.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21301: a Harshad number: divisible by its digit sum 7.
- 2
21301 is composite. Its prime factorisation is
- 3
The divisors add up to 25920; without 21301 itself that is 4619, so 21301 is deficient (4619 is less than 21301). Euler's totient φ(21301) = 17088 numbers up to 21301 share no factor with it.
- 4
The digits of 21301 add up to 7, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 56 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21301 = 7 \times 17 \times 179 \]
21301 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 25920 |
| Euler totient φ(n) | 17088 |
| Square | 453732601 |
| Cube | 9664958133901 |
| Square root | 145.948621 |
| Digit sum / digital root | 7 / 7 |
| Collatz steps to 1 | 56 |
| Scientific notation | 2.1301 × |
21301 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand three hundred and one |
| Binary (base 2) | 101001100110101 |
| Octal (base 8) | 51465 |
| Hexadecimal (base 16) | 5335 |
| Base 3 | 1002012221 |
| As time | 21301 seconds = 5 h 55 min 1 s |
Is 21301 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (21301 ÷ 7 = 3043) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21301 a prime number?
No. 21301 = 7 × 17 × 179, so it is divisible by 7.
What are the factors of 21301?
1, 7, 17, 119, 179, 1253, 3043, 21301.
What is 21301 in binary?
101001100110101 (hexadecimal 5335, octal 51465).
What is the square root of 21301?
About 145.9486.
Is 21301 divisible by 3?
No. Its digits add up to 7, which is not a multiple of 3.
What is special about the number 21301?
21301 is a Harshad number: divisible by its digit sum 7.